# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a191544 Showing 1-1 of 1 %I A191544 #13 Oct 21 2024 01:20:04 %S A191544 1,2,3,4,7,5,9,16,11,6,21,37,25,14,8,49,86,58,32,18,10,114,200,135,74, %T A191544 42,23,12,266,466,315,172,98,53,28,13,620,1087,735,401,228,123,65,30, %U A191544 15,1446,2536,1715,935,532,287,151,70,35,17,3374,5917,4001,2181 %N A191544 Dispersion of (floor(7*n/3)), by antidiagonals. %C A191544 Background discussion: Suppose that s is an increasing sequence of positive integers, that the complement t of s is infinite, and that t(1)=1. The dispersion of s is the array D whose n-th row is (t(n), s(t(n)), s(s(t(n))), s(s(s(t(n)))), ...). Every positive integer occurs exactly once in D, so that, as a sequence, D is a permutation of the positive integers. The sequence u given by u(n)=(number of the row of D that contains n) is a fractal sequence. Examples: %C A191544 (1) s=A000040 (the primes), D=A114537, u=A114538. %C A191544 (2) s=A022343 (without initial 0), D=A035513 (Wythoff array), u=A003603. %C A191544 (3) s=A007067, D=A035506 (Stolarsky array), u=A133299. %C A191544 More recent examples of dispersions: A191426-A191455. %e A191544 Northwest corner: %e A191544 1...2....4....9...21 %e A191544 3...7....16...37..86 %e A191544 5...11...25...58..135 %e A191544 6...14...32...74..172 %e A191544 8...18...42...98..228 %t A191544 (* Program generates the dispersion array T of the complement of increasing sequence f[n] *) %t A191544 r=40; r1=12; c=40; c1=12; f[n_] :=Floor[7n/3]] (* complement of column 1 *) %t A191544 mex[list_] := NestWhile[#1 + 1 &, 1, Union[list][[#1]] <= #1 &, 1, Length[Union[list]]] %t A191544 rows = {NestList[f, 1, c]}; %t A191544 Do[rows = Append[rows, NestList[f, mex[Flatten[rows]], r]], {r}]; %t A191544 t[i_, j_] := rows[[i, j]]; %t A191544 TableForm[Table[t[i, j], {i, 1, 10}, {j, 1, 10}]] %t A191544 (* A191544 array *) %t A191544 Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191544 sequence *) %t A191544 (* Program by _Peter J. C. Moses_, Jun 01 2011 *) %Y A191544 Cf. A114537, A035513, A035506. %K A191544 nonn,tabl %O A191544 1,2 %A A191544 _Clark Kimberling_, Jun 09 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE